(1)
Initial Distribution System
Evaluations.
(a)
General Requirements. The requirements of 310 CMR
22.07F(1) through (6) establish monitoring and other requirements for
identifying Stage 2 DBPR compliance monitoring locations under 310 CMR
22.07(F)
for determining compliance with Maximum Contaminant Levels for Total
Trihalomethanes (TTHM) and Haloacetic Acids (Five) (HAA5). The Supplier of
Water must use an Initial Distribution System Evaluation (IDSE) to determine
locations with representative high TTHM and HAA5 concentrations throughout
their Distribution System. IDSEs are used in conjunction with, but separate
from, compliance monitoring required by 310 CMR
22.07E, to identify and select
compliance monitoring locations under 310 CMR
22.07F(6).
(b)
Applicability.
For Community Water Systems that use a primary or residual Disinfectant other
than ultraviolet light or deliver water that has been treated with a primary or
residual Disinfectant other than ultraviolet light; or a Non-transient
Non-community Water System that serves at least 10,000 people and uses a
primary or residual Disinfectant other than ultraviolet light or delivers water
that has been treated with a primary or residual Disinfectant other than
ultraviolet light.
(c)
Schedule.
1. Each
Supplier of Water must comply with the requirements of the schedule in the
table in 310 CMR
22.20F(1)(c).
TABLE 1 - 310 CMR 22.07F
INITIAL DISTRIBUTION SYSTEM EVALUATION SCHEDULE
|
If you serve this population
|
Supplier of water must submit their standard
monitoring plan or system specific study plan1 or
40/30 certification2 to the Department by or receive
very small system waiver from the Department
|
Supplier of water must complete their standard
monitoring or system specific study by
|
Supplier of water must submit their IDSE report to
the Department by3
|
|
Systems that are not part of a Combined Distribution
System and systems that serve the largest population in the Combined
Distribution System
|
|
a. $100,000
|
October 1, 2006
|
September 30, 2008
|
January 1, 2009
|
|
b. 50,000-99,999
|
April 1, 2007
|
March 31, 2009
|
July 1, 2009
|
|
c. 10,000-49,999
|
October 1, 2007
|
September 30, 2009
|
January 1, 2010
|
|
d. < 10,000 (CWS Only)
|
April 1, 2008
|
March 31, 2010
|
July 1, 2010
|
|
Other systems that are part of a Combined
Distribution System
|
|
e. Wholesale System or consecutive system
|
--at the same time as the system with the earliest
compliance date in the Combined Distribution System
|
--at the same time as the system with the earliest
compliance date in the Combined Distribution System
|
--at the same time as the system with the earliest
compliance date in the Combined Distribution System
|
1 If, within 12 months after the
date identified in this column, the Department does not approve the Supplier of
Water's plan or notify them that it has not yet completed its review, the
Supplier of Water may consider the plan that was submitted as approved.
2 The Supplier of Water must
implement that plan and they must complete standard monitoring or a system
specific study no later than the date identified in the third column. The
supplier of water must submit their 40/30 certification under 310 CMR 22.20F(4)
by the date indicated.
3 If, within three months after the
date identified in this column (nine months after the date identified in this
column if the Supplier of Water must comply on the schedule in 310 CMR
22.07F(1)(c)1.c., the Department does not approve their IDSE report or notify
them that it has not yet completed its review, the Supplier of Water may
consider the report that was submitted as approved and must implement the
recommended monitoring in 310 CMR 22.07F as required.
2. For the purpose of the schedule in 310 CMR
22.07F(1)(c)1., the Department may determine that the Combined Distribution
System does not include certain consecutive systems based on factors such as
receiving water from a Wholesale System only on an Emergency basis or receiving
only a small percentage and small volume of water from a Wholesale System. The
Department may also determine that the Combined Distribution System does not
include certain Wholesale Systems based on factors such as delivering water to
a consecutive system only on an Emergency basis or delivering only a small
percentage and small volume of water to a consecutive system.
(d) The Supplier of Water must
conduct standard monitoring that meets the requirements in 310 CMR
22.20F(2),
or a system specific study that meets the requirements in 310 CMR
22.07F(3), or
certify to the Department that they meet 40/30 certification criteria under 310
CMR
22.20F(4), or qualify for a very small system waiver under 310 CMR
22.07F(5).
1. The Supplier of Water must have
taken the full complement of routine TTHM and HAA5 compliance samples required
of a system with their population and source water under 310 CMR
22.07E (or
they must have taken the full complement of reduced TTHM and HAA5 compliance
samples required of a system with their population and source water under 310
CMR
22.07E if they meet reduced monitoring criteria under 310 CMR
22.07E)
during the period specified in 310 CMR
22.07F(4)(a) to meet the 40/30
certification criteria in 310 CMR
22.07F(4). The Supplier of Water must have
taken TTHM and HAA5 samples under 310 CMR
22.07E(6) and (7) to be eligible for
the very small system waiver in 310 CMR
22.07F(5).
2. If the Supplier of Water has not taken the
required samples, they must conduct standard monitoring that meets the
requirements in 310 CMR
22.07F(2), or a system specific study that meets the
requirements in 310 CMR
22.07F(3).
(e) The Supplier of Water must use only the
analytical methods specified in 310 CMR
22.07E(6), or otherwise approved by EPA
for monitoring under 310 CMR
22.07F, to demonstrate compliance with the
requirements of 310 CMR
22.07F.
(f)
IDSE results will not be used for the purpose of determining compliance with
MCLs in 310 CMR
22.07E(1).
(2)
Standard
Monitoring.
(a)
Standard Monitoring Plan. The standard monitoring plan
must comply with 310 CMR
22.07F(2)(a)1. through 4. The Supplier of Water must
prepare and submit their standard monitoring plan to the Department according
to the schedule in 310 CMR
22.07F(1)(c).
1.
The standard monitoring plan must include a schematic of the Supplier of
Water's Distribution System (including Distribution System entry points and
their sources, and storage facilities), with notes indicating locations and
dates of all projected standard monitoring, and all projected compliance
monitoring required under 310 CMR
22.07E.
2. The standard monitoring plan must include
justification of standard monitoring location selection and a summary of data
relied on to justify standard monitoring location selection.
3. The standard monitoring plan must specify
the population served and system type (Surface Water or Groundwater under the
Direct Influence of Surface Water or Groundwater).
4. The Supplier of Water must retain a
complete copy of their standard monitoring plan submitted under 310 CMR
22.07F(2)(a), including any Department modification of the standard monitoring
plan, for as long as the Supplier of Water is required to retain their IDSE
report under 310 CMR
22.07(2)(c)4.
(b)
Standard
Monitoring.
1. The Supplier of
Water must monitor as indicated in the table in 310 CMR
22.07F(2)(b)1. The
supplier must collect Dual Sample Sets at each monitoring location. One sample
in the Dual Sample Set must be analyzed for TTHM. The other sample in the Dual
Sample Set must be analyzed for HAA5. The Supplier of Water must conduct one
monitoring period during the peak historical month for TTHM levels or HAA5
levels or the month of warmest water temperature. The Supplier of Water must
review available compliance, study, or operational data to determine the peak
historical month for TTHM or HAA5 levels or warmest water temperature.
TABLE 2 - 310 CMR 22.07F
STANDARD MONITORING
|
Source water type
|
Population size category
|
Monitoring periods and frequency of sampling
|
Distribution System monitoring
locations1
|
|
Total per monitoring period
|
Near entry points
|
Average residence Time
|
High TTHM locations
|
High HAA5 locations
|
|
Surface Water and Groundwater under the Direct
Influence of Surface Water
|
<500 consecutive systems
|
One (during peak historical
month)2
|
2
|
1
|
.........
|
1
|
|
<500 non-consecutive systems
|
.........
|
2
|
.........
|
.........
|
1
|
1
|
|
500-3,300 consecutive systems
|
Four (every 90 days)
|
2
|
1
|
.........
|
1
|
|
500-3,300 non-consecutive systems
|
.........
|
2
|
.........
|
.........
|
1
|
1
|
|
3,301-9,999
|
.........
|
4
|
.........
|
1
|
2
|
1
|
|
10,000-49,999
|
Six (every 60 days)
|
8
|
1
|
2
|
3
|
2
|
|
50,000-249,999
|
.........
|
16
|
3
|
4
|
5
|
4
|
|
250,000-999,999
|
.........
|
24
|
4
|
6
|
8
|
6
|
|
1,000,000-4,999,999
|
.........
|
32
|
6
|
8
|
10
|
8
|
|
>=5,000,000
|
.........
|
40
|
8
|
10
|
12
|
10
|
|
Groundwater
|
<500 consecutive systems
|
One (during peak historical
month)2
|
2
|
1
|
.........
|
1
|
|
<500 non-consecutive systems
|
.........
|
2
|
.........
|
.........
|
1
|
1
|
|
500-9,999
|
Four (every 90 days)
|
2
|
.........
|
.........
|
1
|
1
|
|
10,000-99,999
|
.........
|
6
|
1
|
2
|
2
|
|
100,000-499,999
|
.........
|
8
|
1
|
3
|
3
|
|
>=500,000
|
.........
|
12
|
2
|
4
|
4
|
1 A Dual Sample Set
(i.e., a TTHM and an HAA5 sample) must be taken at each
monitoring location during each monitoring period.
2 The peak historical month is the
month with the highest TTHM or HAA5 levels or the warmest water
temperature.
2. The
Supplier of Water must take samples at locations other than the existing
monitoring locations required in 310 CMR
22.07E. Monitoring locations must be
distributed throughout the Distribution System.
3. If the number of entry points to the
Distribution System is fewer than the specified number of entry point
monitoring locations, excess entry point samples must be replaced equally at
high TTHM and HAA5 locations. If there is an odd extra location number, the
Supplier of Water must take a sample at a high TTHM location. If the number of
entry points to the Distribution System is more than the specified number of
entry point monitoring locations, the Supplier of Water must take samples at
entry points to the Distribution System having the highest annual water
flows.
4. The Supplier of Water's
monitoring under 310 CMR
22.07F(2)(b) may not be reduced under the provisions
of 310 CMR
22.12.
(c)
IDSE Report. The Supplier of Water's IDSE report must
include the elements required in 310 CMR
22.07F(2)(c)1. through 4. The Supplier
of Water must submit their IDSE report to the Department according to the
schedule in 310 CMR
22.07F(1)(c).
1. The
Supplier of Water's IDSE report must include all TTHM and HAA5 analytical
results from compliance monitoring under 310 CMR
22.07E and all standard
monitoring conducted during the period of the IDSE as individual analytical
results and LRAAs presented in a tabular or spreadsheet format acceptable to
the Department. If changed from their standard monitoring plan submitted under
310 CMR
22.07F(2)(a), the Supplier of Water's report must also include a
schematic of their Distribution System, the population served, and system type
(Surface Water or Groundwater under the Direct Influence of Surface Water or
Groundwater).
2. The Supplier of
Water's IDSE report must include an explanation of any deviations from their
approved standard monitoring plan.
3. The Supplier of Water must recommend and
justify compliance monitoring locations under 310 CMR
22.07F and timing based
on the protocol in 310 CMR
22.07F(6).
4. The Supplier of Water must retain a
complete copy of their IDSE report submitted under 310 CMR
22.07F(2)(c) for ten
years after the date that they submitted their report. If the Department
modifies the monitoring requirements of 310 CMR
22.07F that the Supplier of
Water recommended in their IDSE report or if the Department approves
alternative monitoring locations, the Supplier of Water must keep a copy of the
Department's notification on file for ten years after the date of the
Department's notification. The Supplier of Water must make the IDSE report and
any Department notification available for review by the Department or the
public.
(3)
System Specific Studies.
(a)
System Specific Study
Plan. The Supplier of Water's system specific study plan must be
based on either existing monitoring results as required under 310 CMR
22.07F(3)(a)1. or modeling as required under 310 CMR
22.07F(3)(a)2. The
Supplier of Water must prepare and submit their system specific study plan to
the Department according to the schedule in 310 CMR
22.07F(1)(c).
1.
Existing Monitoring
Results. The Supplier of Water may comply by submitting monitoring
results collected before they are required to begin monitoring under 310 CMR
22.07F(1)(c). The monitoring results and analysis must meet the criteria in 310
CMR
22.07F(3)(a)1.a and b.
a.
Minimum Requirements.
i. TTHM and HAA5 results must be based on
samples collected and analyzed in accordance with 310 CMR
22.07E(6). Samples
must be collected no earlier than five years prior to the study plan submission
date.
ii. The monitoring locations
and frequency must meet the conditions identified in 310 CMR
22.07F(3)(a)1.a.ii. Each location must be sampled once during the peak
historical month for TTHM levels or HAA5 levels or the month of warmest water
temperature for every 12 months of data submitted for that location. Monitoring
results must include all monitoring results required under 310 CMR
22.07E plus
additional monitoring results as necessary to meet minimum sample requirements.
TABLE 3 - 310 CMR 22.07F
EXISTING MONITORING RESULTS REQUIRED
|
System Type
|
Population size category
|
Number of monitoring locations
|
Number of samples
|
|
TTHM
|
HAA5
|
|
Surface and Groundwater under the Direct Influence of
Surface Water
|
<500
|
3
|
3
|
3
|
|
500-3,300
|
3
|
9
|
9
|
|
3,301-9,999
|
6
|
36
|
36
|
|
10,000 - 49,999
|
12
|
72
|
72
|
|
50,000-249,999
|
24
|
144
|
144
|
|
250,000-999,999
|
36
|
216
|
216
|
|
1,000,000-4,999,999
|
48
|
288
|
288
|
|
>=5,000,000
|
60
|
360
|
360
|
|
Groundwater
|
|
<500
|
3
|
3
|
3
|
|
500-9,999
|
3
|
9
|
9
|
|
10,000-99,999
|
12
|
48
|
48
|
|
100,000-499,999
|
18
|
72
|
72
|
|
>=500,000
|
24
|
96
|
96
|
b.
Reporting Monitoring
Results. The Supplier of Water must report the following
information:
i. The Supplier of Water must
report previously collected monitoring results and certify that the reported
monitoring results include all compliance and non-compliance results generated
during the time period beginning with the first reported result and ending with
the most recent results required under 310 CMR
22.07E.
ii. The Supplier of Water must certify that
the samples were representative of the entire Distribution System and that
treatment, and Distribution System have not changed significantly since the
samples were collected.
iii. The
Supplier of Water's system specific study plan must specify the population
served and system type (Surface Water or Groundwater under the Direct Influence
of Surface Water or Groundwater)
iv. The Supplier of Water's system specific
study plan must specify the population served and system type (Surface Water or
Groundwater under the Direct Influence of Surface Water or
Groundwater)
v. The Supplier of
Water must retain a complete copy of their system specific study plan submitted
under 310 CMR
22.07F(3)(a)1., including any Department modification of their
system specific study plan, for as long as they are required to retain their
IDSE report under 310 CMR
22.07F(3)(b)7.
vi. If the Supplier of Water submits
previously collected data that fully meets the number of samples required under
310 CMR
22.07F(3)(a)1.a.ii. and the Department rejects some of the data, the
Supplier of Water must either conduct additional monitoring to replace rejected
data on a schedule the Department approves or conduct standard monitoring under
310 CMR
22.07F(2).
2.
Modeling. The
Supplier of Water may comply through analysis of an extended period simulation
hydraulic model. The extended period simulation hydraulic model and analysis
must meet the criteria in 310 CMR
22.07F(3)(a)2.
a.
Minimum
Requirements.
i. The model must
simulate 24-hour variation in demand and show a consistently repeating 24 hour
pattern of residence time.
ii.
The model must represent the criteria listed in 310 CMR
22.07F(3)(a)2.a.ii.(A)
through (I).
(A) 75% of pipe
volume;
(B) 50% of pipe
length;
(C) All pressure
zones;
(D) All 12-inch diameter and
larger pipes;
(E) All eight-inch
and larger pipes that connect pressure zones, influence zones from different
sources, storage facilities, major demand areas, pumps, and control valves, or
are known or expected to be significant conveyors of water;
(F) All six-inch and larger pipes that
connect remote areas of a Distribution System to the main portion of the
system;
(G) All storage facilities
with standard operations represented in the model; and
(H) All active pump stations with controls
represented in the model; and
(I)
All active control valves.
iii. The model must be calibrated, or have
calibration plans, for the current configuration of the Distribution System
during the period of high TTHM formation potential. All storage facilities must
be evaluated as part of the calibration process. All required calibration must
be completed no later than 12 months after plan submission.
b.
Reporting
Modeling. The Supplier of Water's system specific study plan must
include the information in 310 CMR
22.07F(3)(a)2.b.
i. Tabular or spreadsheet data demonstrating
that the model meets requirements in 310 CMR
22.07F(3)(a)2.a.ii.
ii. A description of all calibration
activities undertaken, and if calibration is complete, a graph of predicted
tank levels versus measured tank levels for the storage facility with the
highest residence time in each pressure zone, and a time series graph of the
residence time at the longest residence time storage facility in the
Distribution System showing the predictions for the entire simulation period
(i.e., from time zero until the time it takes to for the model
to reach a consistently repeating pattern of residence time).
iii. Model output showing preliminary 24-hour
average residence time predictions throughout the Distribution System.
iv. Timing and number of samples
representative of the Distribution System planned for at least one monitoring
period of TTHM and HAA5 dual sample monitoring at a number of locations no less
than would be required for the system under standard monitoring in 310 CMR
22.07F(2) during the historical month of high TTHM. These samples must be taken
at locations other than existing compliance monitoring locations under 310 CMR
22.07E.
v. Description of how all
requirements will be completed no later than 12 months after the Supplier of
Water submits their system specific study plan.
vi. Schematic of the Supplier of Water's
Distribution System (including Distribution System entry points and their
sources, and storage facilities), with notes indicating the locations and dates
of all completed system specific study monitoring (if calibration is complete)
and all compliance monitoring required under 310 CMR
22.07E.
vii. Population served and system type
(Surface Water and Groundwater Under the Direct Influence of Surface Water or
Groundwater).
viii. The Supplier
of Water must retain a complete copy of their system specific study plan
submitted under 310 CMR
22.07F(3)(a)2., including any Department modification
of the system specific study plan, for as long as the Supplier of Water is
required to retain their IDSE report under 310 CMR
22.07F(3)(b)7.
c. If the Supplier of Water
submits a model that does not fully meet the requirements under 310 CMR
22.07F(3)(a)2., the Supplier of Water must correct the deficiencies and respond
to Department inquiries concerning the model. If the Supplier of Water fails to
correct deficiencies or respond to inquiries to the Department's satisfaction,
they must conduct standard monitoring under 310 CMR
22.07F(2).
(b)
IDSE Report. The Supplier of Water's IDSE report must
include the elements required in 310 CMR
22.07F(3)(b)1. through 6. The Supplier
of Water must submit their IDSE report according to the schedule in 310 CMR
22.07F(1)(c).
1. The Supplier of Water's IDSE
report must include all TTHM and HAA5 analytical results from monitoring
required under 310 CMR
22.07E and all system specific study monitoring
conducted during the period of the system specific study presented in a tabular
or spreadsheet format acceptable to the Department. If changed from the
Supplier of Water's system specific study plan submitted under 310 CMR
22.07F(3)(a), their IDSE report must also include a schematic of their
Distribution System, the population served, and system type (Surface Water and
Groundwater under the Direct Influence of Surface Water or
Groundwater).
2. If the Supplier of
Water used the modeling provision under 310 CMR
22.07F(3)(a)2., they must
include final information for the elements described in 310 CMR
22.07F(3)(a)2.b., and a 24-hour time series graph of residence time for each
compliance monitoring location selected in 310 CMR
22.07F.
3. The Supplier of Water must recommend and
justify compliance monitoring locations in 310 CMR
22.07F and timing based on
the protocol in 310 CMR
22.07(6).
4. The Supplier of Water's IDSE report must
include an explanation of any deviations from their approved system specific
study plan.
5. The Supplier of
Water's IDSE report must include the basis (analytical and modeling results)
and justification they used to select the recommended monitoring locations in
310 CMR
22.07F(6).
6. The Supplier
of Water may submit their IDSE report in lieu of their system specific study
plan on the schedule identified in 310 CMR
22.07F(1)(c) for submission of the
system specific study plan if they believe that they have the necessary
information by the time that the system specific study plan is due. If the
Supplier of Water elects this approach, their IDSE report must also include all
information required under 310 CMR
22.07F(3)(a).
7. The Supplier of Water must retain a
complete copy of their IDSE report submitted under 310 CMR
22.07F(3)(b) for ten
years after the date that they submitted their IDSE report. If the Department
modifies the monitoring requirements in 310 CMR
22.07F that the Supplier of
Water recommended in their IDSE report or if the Department approves
alternative monitoring locations, the Supplier of Water must keep a copy of the
Department's notification on file for ten years after the date of the
Department's notification. The Supplier of Water must make the IDSE report and
any Department notification available for review by the Department or the
public.
(4)
40/30 Certification.
(a)
Eligibility. The
Supplier of Water is eligible for 40/30 certification if they had no TTHM or
HAA5 monitoring violations under 310 CMR
22.07E and no individual sample
exceeded 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 during an eight consecutive
calendar quarter period beginning no earlier than the date specified in 310 CMR
22.07F(4)(a).
TABLE 4 - 310 CMR 22.07F
40/30 CERTIFICATION SCHEDULE
|
If your 40/30 certification is due
|
Then your eligibility for 40/30 certification is
based on eight consecutive calendar quarters of compliance monitoring results
under 310 CMR 22.07E beginning no earlier
than1
|
|
1. October 1, 2006
|
January 2004
|
|
2. April 1, 2007
|
January 2004
|
|
3. October 1, 2007
|
January 2005
|
|
4. April 1, 2008
|
January 2005
|
1 Unless the Supplier of Water is on
reduced monitoring under 310 CMR 22.07E and was not required to monitor during
the specified period. If they did not monitor during the specified period, they
must base their eligibility on compliance samples taken during the 12 months
preceding the specified period.
(b)
40/30
Certification.
1. The Supplier of
Water must certify to the Department that every individual compliance sample
taken under 310 CMR
22.07E during the periods specified in 310 CMR
22.07F(4)(a)
were <= 0.040 mg/L for TTHM and <= 0.030 mg/L for HAA5, and that they
have not had any TTHM or HAA5 monitoring violations during the period specified
in 310 CMR
22.07F(4)(a).
2. The
Department may require the Supplier of Water to submit compliance monitoring
results, Distribution System schematics, and/or recommended compliance
monitoring locations as required in 310 CMR
22.07F in addition to their
certification. If the Supplier of Water fails to submit the requested
information, the Department may require standard monitoring under 310 CMR
22.07F(2) or a system specific study under 310 CMR
22.07F(3).
3. The Department may still require standard
monitoring under 310 CMR
22.07F(2) or a system specific study under 310 CMR
22.07F(3) even if the Supplier of Water meets the criteria in 310 CMR
22.07F(4)(a).
4. The Supplier of
Water must retain a complete copy of their certification submitted under 310
CMR
22.07F(4)(b) for ten years after the date that they submitted their
certification. The Supplier of Water must make the certification, all data upon
which the certification is based, and any Department notification available for
review by the Department or the public.
(5)
Very Small System
Waivers.
(a) If the Supplier of
Water serves fewer than 500 people and it has taken TTHM and HAA5 samples under
310 CMR
22.07E, the Supplier of Water is not required to comply with 310 CMR
22.07F(1) unless the Department notifies the Supplier of Water that it must
conduct standard monitoring under 310 CMR
22.07F(2) or a system specific study
under 310 CMR
22.07F(3).
(b) If the
Supplier of Water has not taken TTHM and HAA5 samples under 310 CMR
22.07E or
if the Department notifies the Supplier of Water that it must comply with 310
CMR
22.07F(1), the Supplier of Water must conduct standard monitoring under 310
CMR
22.07F(2) or a system specific study under 310 CMR
22.07F(3).
(6)
Compliance
Monitoring Location Recommendations.
(a) The Supplier of Water's IDSE report must
include their recommendations and justification for where and during what
month(s) TTHM and HAA5 monitoring required under 310 CMR
22.07F(8) should be
conducted. They must base their recommendations on the criteria in 310 CMR
22.07F(6)(b) through (e).
(b) The
Supplier of Water must select the number of monitoring locations specified in
the table in 310 CMR
22.07F(6)(b). The Supplier of Water will use these
recommended locations as routine compliance monitoring locations under 310 CMR
22.07F, unless the Department requires different or additional locations. The
Supplier of Water should distribute locations throughout the Distribution
System to the extent possible.
TABLE 5 - 310 CMR 22.07F
DISTRIBUTION SYSTEM MONITORING LOCATIONS
|
Distribution System monitoring location
|
|
Source water type
|
Population size category
|
Monitoring
frequency1
|
Total per monitoring
period2
|
Highest TTHM locations
|
Highest HAA5 locations
|
Existing compliance locations under 310 CMR
22.07E
|
|
Surface or Groundwater under the Direct Influence of
Surface Water
|
<500
|
Per year
|
2
|
1
|
1
|
...........
|
|
500-3,300
|
Per quarter
|
2
|
1
|
1
|
|
3,301-9,999
|
Per quarter
|
2
|
1
|
1
|
...........
|
|
10,000-49,999
|
Per quarter
|
4
|
2
|
1
|
1
|
|
50,000-249,999
|
Per quarter
|
8
|
3
|
3
|
2
|
|
250,000-999,999
|
Per quarter
|
12
|
5
|
4
|
3
|
|
1,000,000-4,999,999
|
Per quarter
|
16
|
6
|
6
|
4
|
|
>=5,000,000
|
Per quarter
|
20
|
8
|
7
|
5
|
|
Groundwater
|
|
<500
|
Per year
|
2
|
1
|
1
|
|
500-9,999
|
Per year
|
2
|
1
|
1
|
|
10,000-99,999
|
Per quarter
|
4
|
2
|
1
|
1
|
|
100,000-499,999
|
Per quarter
|
6
|
3
|
2
|
1
|
|
>=500,000
|
Per quarter
|
8
|
3
|
3
|
2
|
1 All systems must monitor during
month of highest DBP concentrations.
2 Systems on quarterly monitoring
must take Dual Sample Sets every 90 days at each monitoring location, except
for Surface Water and Groundwater under the Direct Influence of Surface Water
systems serving 500-3,300. Groundwater systems serving 500 9,999 on annual
monitoring must take Dual Sample Sets at each monitoring location. All other
systems on annual monitoring and Surface Water and Groundwater under the Direct
Influence of Surface Water systems serving 500-3,300 are required to take
individual TTHM and HAA5 samples (instead of a Dual Sample Set) at the
locations with the highest TTHM and HAA5 concentrations, respectively. For
systems serving fewer than 500 people, only one location with a Dual Sample Set
per monitoring period is needed if highest TTHM and HAA5 concentrations occur
at the same location and month.
(c) The Supplier of Water must recommend
compliance monitoring locations for 310 CMR
22.07F(6) based on standard
monitoring results, system specific study results, and compliance monitoring
results required under 310 CMR
22.07E. The Supplier of Water must follow the
protocol in 310 CMR
22.07F(6)(c)1. through 8. If required to monitor at more
than eight locations, the Supplier of Water must repeat the protocol as
necessary. If the Supplier of Water does not have existing compliance
monitoring results required under 310 CMR
22.07E or if they do not have enough
existing compliance monitoring results required under 310 CMR
22.07E, they must
repeat the protocol, skipping the provisions of 310 CMR
22.07F(6)(c)(3) and (7)
as necessary, until they have identified the required total number of
monitoring locations.
1. Location with the
highest TTHM LRAA not previously selected as a monitoring location under 310
CMR
22.07F.
2. Location with the
highest HAA5 LRAA not previously selected as a monitoring location under 310
CMR
22.07F.
3. Existing average
residence time compliance monitoring location (maximum residence time
compliance monitoring location for groundwater systems) under 310 CMR
22.07E
with the highest HAA5 LRAA not previously selected as a monitoring location
under 310 CMR
22.07F.
4. Location
with the highest TTHM LRAA not previously selected as a monitoring location
under 310 CMR
22.07F.
5. Location
with the highest TTHM LRAA not previously selected as a monitoring location
under 310 CMR
22.07F.
6. Location
with the highest HAA5 LRAA not previously selected as a monitoring location
under 310 CMR
22.07F.
7. Existing
average residence time compliance monitoring location (maximum residence time
compliance monitoring location for groundwater systems) under 310 CMR
22.07E
with the highest TTHM LRAA not previously selected as a monitoring location
under 310 CMR
22.07F.
8. Location
with the highest HAA5 LRAA not previously selected as a monitoring location
under 310 CMR
22.07F.
(d) The Supplier of Water may recommend
locations other than those specified in 310 CMR
22.07F(6)(c) if they include a
rationale for selecting other locations. If the Department approves the
alternate locations, they must monitor at these locations to determine
compliance under 310 CMR
22.07F.
(e) The Supplier of Water's recommended
schedule must include monitoring required under 310 CMR
22.07F during the peak
historical month for TTHM and HAA5 concentration, unless the Department
approves another month. Once the Supplier of Water has identified the peak
historical month, and if they are required to conduct routine monitoring at
least quarterly, they must schedule compliance monitoring required under 310
CMR
22.07F at a regular frequency of every 90 days or fewer.
(7)
General Monitoring
Requirements of Stage 2 Disinfection Byproducts Rule.
(a)
General. The
requirements of 310 CMR
22.07F(7) through (16) establish monitoring and other
requirements for achieving compliance with Maximum Contaminant Levels based on
Locational Running Annual Averages (LRAA) for Total Trihalomethanes (TTHM) and
Haloacetic Acids (Five) (HAA5), and for achieving compliance with maximum
residual Disinfectant residuals for chlorine and chloramine for certain
consecutive systems.
(b)
Applicability. The Supplier of Water is subject to
these requirements if their system is a Community Water System or a
Non-transient Non-community Water System that uses a primary or residual
Disinfectant other than ultraviolet light or delivers water that has been
treated with a primary or residual Disinfectant other than ultraviolet
light.
(c)
Schedule. The Supplier of Water must comply with the
requirements in 310 CMR
22.07F(7) on the schedule in the following table based
on their system type.
TABLE 6 - 310 CMR 22.07F
MONITORING SCHEDULE
|
If you are this type of system
|
You must comply with monitoring required under 310
CMR 22.07F(7) by:1
|
|
Systems that are not part of a Combined Distribution
System and systems that serve the largest population in the Combined
Distribution System
|
|
1. System serving >= 100,000
|
April 1, 2012
|
|
2. System serving 50,000 99,999
|
October 1, 2012
|
|
3. System serving 10,000 49,999
|
October 1, 2013
|
|
4. System serving < 10,000
|
October 1, 2013 if no
Cryptosporidium monitoring is required under 310 CMR
22.20G(2)(a)4. or
October 1, 2014 if Cryptosporidium
monitoring is required under 310 CMR 22.20G(2)(a)4. or 310 CMR
22.20G(2)(a)6.
|
|
Other systems that are part of a Combined
Distribution System
|
|
5. Consecutive system or Wholesale System
|
at the same time as the system with the earliest
compliance date in the Combined Distribution System.
|
1 The Department may grant up to an
additional 24 months for compliance with MCLs and operational evaluation levels
if the Supplier of Water requires capital improvements to comply with an
MCL.
6. The Supplier of Water's
monitoring frequency is specified in 310 CMR
22.07F(8)(a)2.
a. If the Supplier of Water is required to
conduct quarterly monitoring, they must begin monitoring in the first full
calendar quarter that includes the compliance date in the table in 310 CMR
22.07F(7)(c).
b. If the Supplier of
Water is required to conduct monitoring at a frequency that is less than
quarterly, they must begin monitoring in the calendar month recommended in the
IDSE report prepared under 310 CMR
22.07F(2) or (3) or the calendar month
identified in the monitoring plan developed under 310 CMR
22.07F(9) no later
than 12 months after the compliance date in the table in 310 CMR
22.07F(7)(c).
7. If the
Supplier of Water is required to conduct quarterly monitoring, they must make
compliance calculations at the end of the fourth calendar quarter that follows
the compliance date and at the end of each subsequent quarter (or earlier if
the LRAA calculated based on fewer than four quarters of data would cause the
MCL to be exceeded regardless of the monitoring results of subsequent
quarters). If the Supplier of Water is required to conduct monitoring at a
frequency that is less than quarterly, they must make compliance calculations
beginning with the first compliance sample taken after the compliance
date.
8. For the purpose of the
schedule in 310 CMR
22.07F(7)(c), the Department may determine that the
Combined Distribution System does not include certain consecutive systems based
on factors such as receiving water from a Wholesale System only on an Emergency
basis or receiving only a small percentage and small volume of water from a
Wholesale System. The Department may also determine that the Combined
Distribution System does not include certain Wholesale Systems based on factors
such as delivering water to a consecutive system only on an Emergency basis or
delivering only a small percentage and small volume of water to a consecutive
system.
(d)
Monitoring and Compliance.
1.
Systems Required to Monitor
Quarterly. To comply with MCLs required by 310 CMR
22.07F listed
in 310 CMR
22.07E(1), the Supplier of Water must calculate LRAAs for TTHM and
HAA5 using monitoring results collected under 310 CMR
22.07F and determine that
each LRAA does not exceed the MCL. If the Supplier of Water fails to complete
four consecutive quarters of monitoring, they must calculate compliance with
the MCL based on the average of the available data from the most recent four
quarters. If the Supplier of Water takes more than one sample per quarter at a
monitoring location, they must average all samples taken in the quarter at that
location to determine a quarterly average to be used in the LRAA
calculation.
2.
Systems
Required to Monitor Yearly or less Frequently. To determine
compliance with MCLs required by 310 CMR
22.07F listed in 310 CMR
22.07E(1),
the Supplier of Water must determine that each sample taken is less than the
MCL. If any sample exceeds the MCL, they must comply with the requirements of
310 CMR
22.07F(12). If no sample exceeds the MCL, the sample result for each
monitoring location is considered the LRAA for that monitoring
location.
(e)
Violation. The Supplier of Water is in violation of
the monitoring requirements for each quarter that a monitoring result would be
used in calculating an LRAA if they fail to monitor.
(8)
Routine
Monitoring.
(a)
Monitoring.
1. If
the water supplier submitted an IDSE report, they must begin monitoring at the
locations and months they have recommended in their IDSE report submitted under
310 CMR
22.07F(6) following the schedule in 310 CMR
22.07F(7)(c), unless the
Department requires other locations or additional locations after its review.
If the Supplier of Water submitted a 40/30 certification under 310 CMR
22.07F(4) or they qualified for a very small system waiver under 310 CMR
22.07F(5) or they are a Non-transient Non-community Water System serving <
10,000, they must monitor at the location(s) and dates identified in their
monitoring plan in 310 CMR
22.07E(7)(f) updated as required by 310 CMR
22.07F(9).
2. The Supplier of Water
must monitor at no fewer than the number of locations identified in 310 CMR
22.07F(8)(a)2.
TABLE 7 - 310 CMR 22.07F
ROUTINE MONITORING FREQUENCY
|
Source Water Type
|
Population Size Category
|
Monitoring Frequency
1
|
Distribution System monitoring location total per
monitoring period
2
|
|
Surface Water and Groundwater under the Direct
Influence of Surface Water
|
<500
|
Per year
|
2
|
|
500-3,300
|
Per quarter
|
2
|
|
3,301-9,999
|
Per quarter
|
2
|
|
10,000-49,999
|
Per quarter
|
4
|
|
50,000-249,999
|
Per quarter
|
8
|
|
250,000-999,999
|
Per quarter
|
12
|
|
1,000,000-4,999,999
|
Per quarter
|
16
|
|
>=5,000,000
|
Per quarter
|
20
|
|
Groundwater
|
|
<500
|
Per year
|
2
|
|
500-9,999
|
Per year
|
2
|
|
10,000-99,999
|
Per quarter
|
4
|
|
100,000-499,999
|
Per quarter
|
6
|
|
>=500,000
|
Per quarter
|
8
|
1 All systems must monitor during
month of highest DBP concentrations.
2 Systems on quarterly monitoring
must take Dual Sample Sets every 90 days at each monitoring location, except
for systems using Surface Water or Groundwater under the Direct Influence of
Surface Water systems and serving 500-3,300. Groundwater systems serving
500-9,999 on annual monitoring must take Dual Sample Sets at each monitoring
location. All other systems on annual monitoring and systems using Surface
Water or groundwater systems under the direct influence of surface water
systems serving 500-3,300 are required to take individual TTHM and HAA5 samples
(instead of a Dual Sample Set) at the locations with the highest TTHM and HAA5
concentrations, respectively. For systems serving fewer than 500 people, only
one location with a Dual Sample Set per monitoring period is needed if highest
TTHM and HAA5 concentrations occur at the same location and month.
3. If the Supplier of Water is an
undisinfected system that begins using a Disinfectant other than UV light after
the dates in 310 CMR
22.07F(1) for complying with the Initial Distribution
System Evaluation requirements, they must consult with the Department to
identify compliance monitoring locations for 310 CMR
22.07F(8). The Supplier of
Water must then develop a monitoring plan under 310 CMR
22.07F(9) that includes
those monitoring locations.
(b)
Analytical
Methods. The Supplier of Water must use an approved method listed
in 310 CMR
22.07E(6) for TTHM and HAA5 analyses in 310 CMR
22.07F(8). Analyses
must be conducted by laboratories that have received certification by EPA or
the Department as specified in 310 CMR
22.07E(6).
(9)
Monitoring Plan.
(a)
1. The
Supplier of Water must develop and implement a monitoring plan to be kept on
file for Department and public review. The monitoring plan must contain the
elements in 310 CMR
22.07F(9)(a)1.a. through d. and be completed no later than
the date the Supplier of Water conducts their initial monitoring under 310 CMR
22.07F(8).
a. Monitoring locations;
b. Monitoring dates;
c. Compliance calculation procedures;
and
d. Monitoring plans for any
other systems in the Combined Distribution System if the Department has reduced
monitoring requirements.
2. If the Supplier of Water was not required
to submit an IDSE report under either 310 CMR
22.07F(2) or (3), and they do not
have sufficient monitoring locations required under 310 CMR
22.07E to identify
the required number of compliance monitoring locations indicated in 310 CMR
22.07F(6)(b), they must identify additional locations by alternating selection
of locations representing high TTHM levels and high HAA5 levels until the
required number of compliance monitoring locations have been identified. They
must also provide the rationale for identifying the locations as having high
levels of TTHM or HAA5. If the Supplier of Water has more monitoring locations
required under 310 CMR
22.07E than required for compliance monitoring in 310
CMR
22.07F(6)(b), they must identify which locations they will use for
compliance monitoring under 310 CMR
22.07F(8) by alternating selection of
locations representing high TTHM levels and high HAA5 levels until the required
number of compliance monitoring locations under 310 CMR
22.07F(8) have been
identified.
(b) If the
Supplier of Water is a Surface Water or a Groundwater under the Direct
Influence of Surface Water serving > 3,300 people, they must submit a copy
of their monitoring plan to the Department prior to the date they conduct their
initial monitoring under 310 CMR
22.07F(8), unless their IDSE report submitted
under 310 CMR
22.07F(2) contains all the information required by 310 CMR
22.07F(9).
(c) The Supplier of
Water may revise their monitoring plan to reflect changes in treatment,
Distribution System operations and layout (including new service areas), or
other factors that may affect TTHM or HAA5 formation, or for
Department-approved reasons, after consultation with the Department regarding
the need for changes and the appropriateness of changes. If the Supplier of
Water changes monitoring locations, they must replace existing compliance
monitoring locations with the lowest LRAA with new locations that reflect the
current Distribution System locations with expected high TTHM or HAA5 levels.
The Department may also require modifications in their monitoring plan. If they
are a Surface Water or Groundwater under the Direct Influence of Surface Water
system serving > 3,300 people, they must submit a copy of their modified
monitoring plan to the Department prior to the date they are required to comply
with the revised monitoring plan.
(10)
Reduced
Monitoring.
(a) The Supplier of
Water may reduce monitoring to the level specified in the table in 310 CMR
22.07F(10)(a) any time the LRAA is <= 0.040 mg/L for TTHM and <=
0.030mg/L for HAA5 at all monitoring locations. They may only use data
collected under the provisions of 310 CMR
22.07E or
22.07F to qualify for
reduced monitoring. In addition, the source water annual average TOC level,
before any treatment, must be <= 4.0 mg/L at each treatment plant treating
Surface Water or Groundwater Under the Direct Influence of Surface Water, based
on monitoring conducted under 310 CMR
22.07E(7)(b)1.c. or (d).
TABLE 8 - 310 CMR 22.07F
REDUCED MONITORNG FREQUENCY AND LOCATION
|
Source water type
|
Population size category
|
Monitoring
frequency1
|
Distribution System monitoring location per
monitoring period
|
|
Surface Water or Groundwater under the Influence of
Surface Water
|
<500
|
...................
|
Monitoring may not be reduced.
|
|
500-3,300
|
Per year
|
1 TTHM and 1 HAA5 sample: one at the location and
during the quarter with the highest TTHM single measurement, one at the
location and during the quarter with the highest HAA5 single measurement; 1
Dual Sample Set per year if the highest TTHM and HAA5 measurements occurred at
the same location and quarter.
|
|
3,301-9,999
|
Per year
|
2 Dual Sample Sets: one at the location and during
the quarter with the highest TTHM single measurement, one at the location and
during the quarter with the highest HAA5 single measurement.
|
|
10,000-49,999
|
Per quarter
|
2 Dual Sample Sets at the locations with the highest
TTHM and highest HAA5 LRAAs.
|
|
50,000-249,999
|
Per quarter
|
4 Dual Sample Sets at the locations with the two
highest TTHM and two highest HAA5 LRAAs.
|
|
250,000-999,999
|
Per quarter
|
6 Dual Sample Sets at the locations with the three
highest TTHM and three highest HAA5 LRAAs.
|
|
1,000,000-4,999,999
|
Per quarter
|
8 Dual Sample Sets at the locations with the four
highest TTHM and four highest HAA5 LRAAs.
|
|
>=5,000,000
|
Per quarter
|
10 Dual Sample Sets at the locations with the five
highest TTHM and five highest HAA5 LRAAs.
|
|
Groundwater
|
|
<500
|
Every third year
|
1 TTHM and 1 HAA5 sample: one at the location and
during the quarter with the highest TTHM single measurement, one at the
location and during the quarter with the highest HAA5 single measurement; 1
Dual Sample Set per year if the highest TTHM and HAA5 measurements occurred at
the same location and quarter.
|
|
500-9,999
|
Per year
|
1 TTHM and 1 HAA5 sample: one at the location and
during the quarter with the highest TTHM single measurement, one at the
location and during the quarter with the highest HAA5 single measurement; 1
Dual Sample Set per year if the highest TTHM and HAA5 measurements occurred at
the same location and quarter.
|
|
10,000-99,999
|
Per year
|
2 Dual Sample Sets: one at the location and during
the quarter with the highest TTHM single measurement, one at the location and
during the quarter with the highest HAA5 single measurement.
|
|
100,000-499,999
|
Per quarter
|
2 Dual Sample Sets at the locations with the highest
TTHM and highest HAA5 LRAAs.
|
|
>=500,000
|
Per quarter
|
4 Dual Sample Sets at the locations with the two
highest TTHM and two highest HAA5 LRAAs.
|
1 Systems on quarterly monitoring
must take Dual Sample Sets every 90 days.
(b) The Supplier of Water may remain on
reduced monitoring as long as the TTHM LRAA <= 0.040 mg/L and the HAA5 LRAA
<= 0.030 mg/L at each monitoring location (for systems with quarterly
reduced monitoring) or each TTHM sample <= 0.060 mg/L and each HAA5 sample
<= 0.045 mg/L (for systems with annual or less frequent monitoring). In
addition, the source water annual average TOC level, before any treatment, must
be <= 4.0 mg/L at each treatment plant treating Surface Water or Groundwater
under the Direct Influence of Surface Water, based on monitoring conducted
under either 310 CMR
22.07E(7)(b)1.c. or (d).
(c) If the LRAA based on quarterly monitoring
at any monitoring location exceeds either 0.040 mg/L for TTHM or 0.030 mg/L for
HAA5 or if the annual (or less frequent) sample at any location exceeds either
0.060 mg/L for TTHM or 0.045 mg/L for HAA5, or if the source water annual
average TOC level, before any treatment, >4.0 mg/L at any treatment plant
treating Surface Water or Groundwater Under the Direct Influence of Surface
Water, the Supplier of Water must resume routine monitoring under 310 CMR
22.07F(8) or begin increased monitoring if 310 CMR
22.07F(12)
applies.
(d) The Department may
return the Supplier of Water to routine monitoring at the Department's
discretion.
(11)
Additional Requirements for Consecutive Systems. If
the Supplier of Water is a consecutive system that does not add a Disinfectant
but delivers water that has been treated with a primary or residual
Disinfectant other than ultraviolet light, they must comply with analytical and
monitoring requirements for chlorine and chloramines in 310 CMR
22.07E(6)(c)
and (7)(c)1. and the compliance requirements in 310 CMR
22.07E(8)(c)1.
beginning April 1, 2009, unless required earlier by the Department, and report
monitoring results under 310 CMR
22.07E(9)(c).
(12)
Conditions Requiring
Increased Monitoring.
(a) If the
Supplier of Water is required to monitor at a particular location annually or
less frequently than annually under 310 CMR
22.07F(8) or (10), they must
increase monitoring to Dual Sample Sets once per quarter (taken every 90 days)
at all locations if a TTHM sample is >0.080 mg/L or a HAA5 sample is
>0.060 mg/L at any location.
(b)
The Supplier of Water is in violation of the MCL when the LRAA exceeds the
Stage 2 Disinfection Byproducts MCLs in 310 CMR
22.07E(1), calculated based on
four consecutive quarters of monitoring (or the LRAA calculated based on fewer
than four quarters of data if the MCL would be exceeded regardless of the
monitoring results of subsequent quarters). The Supplier of Water is in
violation of the monitoring requirements for each quarter that a monitoring
result would be used in calculating an LRAA if they fail to monitor.
(c) The Supplier of Water may return to
routine monitoring once they have conducted increased monitoring for at least
four consecutive quarters and the LRAA for every monitoring location is <=
0.060 mg/L for TTHM and <= 0.045 mg/L for HAA5.
(13)
Operational Evaluation
Levels.
(a) The Supplier of Water
has exceeded the operational evaluation level at any monitoring location where
the sum of the two previous quarters' TTHM results plus twice the current
quarter's TTHM result, divided by four to determine an average, exceeds 0.080
mg/L, or where the sum of the two previous quarters' HAA5 results plus twice
the current quarter's HAA5 result, divided by four to determine an average,
exceeds 0.060 mg/L.
(b)
1. If the Supplier of Water exceeds the
operational evaluation level, they must conduct an operational evaluation and
submit a written report of the evaluation to the Department no later than 90
days after being notified of the analytical result that causes them to exceed
the operational evaluation level. The written report must be made available to
the public upon request.
2. The
Supplier of Water's operational evaluation must include an examination of
system treatment and distribution operational practices, including storage tank
operations, excess storage capacity, Distribution System flushing, changes in
sources or source water quality, and treatment changes or problems that may
contribute to TTHM and HAA5 formation and what steps could be considered to
minimize future exceedences.
a. The Supplier
of Water may request and the Department may allow them to limit the scope of
their evaluation if they are able to identify the cause of the operational
evaluation level exceedance.
b. The
Supplier of Water's request to limit the scope of the evaluation does not
extend the schedule in 310 CMR
22.07F(13)(b)1. for submitting the written
report. The Department must approve this limited scope of evaluation in writing
and the Supplier of Water must keep that approval with the completed
report.
(14)
Requirements for Remaining
on Reduced TTHM and HAA5 Monitoring Based on Results Required under 310 CMR
22.07E. The Supplier of Water may remain on reduced monitoring
after the dates identified in 310 CMR
22.07F(7)(c) for compliance with 310 CMR
22.07F(14) only if they qualify for a 40/30 certification under 310 CMR
22.07F(4) or have received a very small system waiver under 310 CMR
22.07F(5),
plus they meet the reduced monitoring criteria in 310 CMR
22.07F(10)(a), and
they do not change or add monitoring locations from those used for compliance
monitoring under 310 CMR
22.07E. If the Supplier of Water's monitoring
locations under 310 CMR
22.07F differ from their monitoring locations under 310
CMR
22.07E, they may not remain on reduced monitoring after the dates
identified in 310 CMR
22.07F(7)(c) for compliance with 310 CMR
22.07F.
(15) Requirements for
Remaining on Increased TTHM and HAA5 Monitoring Based on Results Required under
310 CMR
22.07E. If the Supplier of Water was on increased monitoring under 310
CMR
22.07E(7)(b)1., they must remain on increased monitoring until they qualify
for a return to routine monitoring under 310 CMR
22.07F(12)(c). The Supplier of
Water must conduct increased monitoring under 310 CMR
22.07F(12) at the
monitoring locations in the monitoring plan developed under 310 CMR
22.07F(9)
beginning at the date identified in 310 CMR
22.07F(7)(c) for compliance with
310 CMR
22.07F and remain on increased monitoring until they qualify for a
return to routine monitoring under 310 CMR
22.07F(12)(c).
(16)
Reporting and Recordkeeping
Requirements.
(a)
Reporting.
1. The
Supplier of Water must report the following information for each monitoring
location to the Department within ten days of the end of any quarter in which
monitoring is required:
a. Number of samples
taken during the last quarter.
b.
Date and results of each sample taken during the last quarter.
c. Arithmetic average of quarterly results
for the last four quarters for each monitoring location (LRAA), beginning at
the end of the fourth calendar quarter that follows the compliance date and at
the end of each subsequent quarter. If the LRAA calculated based on fewer than
four quarters of data would cause the MCL to be exceeded regardless of the
monitoring results of subsequent quarters, they must report this information to
the Department as part of the first report due following the compliance date or
anytime thereafter that this determination is made. If the Supplier of Water is
required to conduct monitoring at a frequency that is less than quarterly, they
must make compliance calculations beginning with the first compliance sample
taken after the compliance date, unless they are required to conduct increased
monitoring under 310 CMR
22.07F(12).
d. Whether, based on 310 CMR
22.07E(1) and
22.07F, the MCL was violated at any monitoring location.
e. Any operational evaluation levels that
were exceeded during the quarter and, if so, the location and date, and the
calculated TTHM and HAA5 levels.
2. If the Supplier of Water is a Surface
Water or Groundwater under the Direct Influence of Surface Water system seeking
to qualify for or remain on reduced TTHM/HAA5 monitoring, they must report the
following source water TOC information for each treatment plant that treats
Surface Water or Groundwater under the Direct Influence of Surface Water to the
Department within ten days of the end of any quarter in which monitoring is
required:
a. The number of source water TOC
samples taken each month during last quarter.
b. The date and result of each sample taken
during last quarter.
c. The
quarterly average of monthly samples taken during last quarter or the result of
the quarterly sample.
d. The
Running Annual Average (RAA) of quarterly averages from the past four
quarters.
e. Whether the RAA
exceeded 4.0 mg/L.
3.
The Department may choose to perform calculations and determine whether the MCL
was exceeded or the system is eligible for reduced monitoring in lieu
of having the system report that information.
(b)
Recordkeeping.
The Supplier of Water must retain any monitoring plans required under
310 CMR
22.07F and their monitoring results as
required by
310
CMR
22.07E(8).
